CONTROL AS-ELECTRONIC 2762672 - Caterpillar

Illustration 6 g00874461
View C-C (7) Steering control valve (BB) Pressure tap for oil in the secondary steering circuit
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View D-D (12) Steering piston pump (14) Low oil pressure switch for the steering pumps (15) Orifice (16) Pressure compensator valve (AA) Pressure tap for oil from the steering piston pumpOperation
The steering system is hydraulic. There is no mechanical connection between the steering wheel and steering cylinders (4) that move the front wheels. The steering system is a closed center system. The steering system is independent of all other hydraulic systems. Oil for the steering system is stored in steering hydraulic tank (10).
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(12) Steering piston pump (14) Low oil pressure switch for the steering pumps (16) Pressure compensator valve (17) Pump drive (AA) Pressure tap for oil from the steering piston pumpSteering piston pump (12) is a pressure compensated piston type pump. The steering piston pump, the hoist and front brake cooling gear pump, and the rear brake cooling and parking brake release gear pump are driven by pump drive (17). Pump drive (17) is on the right hand frame rail near the rear of the flywheel housing. Pump drive (17) is driven by a drive shaft. The drive shaft is connected between the pump drive and the engine. Steering piston pump (12) operates only when the engine is running.The maximum outlet pressure of the steering piston pump is controlled by accumulator charging valve (3). The cutoff valve in accumulator charging valve (3) will signal pressure compensator valve (16) to destroke the steering piston pump when the steering accumulators are full.Pressure compensator valve (16) is fastened to steering piston pump (12). Pressure compensator valve (16) determines the swashplate angle of the steering piston pump. The high pressure cutoff valve in pressure compensator valve (16) is set at a higher pressure than the cutoff valve in accumulator charging valve (3). If the steering accumulators are full and accumulator charging valve (3) does not send a signal, the high pressure cutoff valve in pressure compensator valve (16) will destroke the steering piston pump.The low pressure standby pressure of the steering piston pump is controlled by the low pressure cut-in valve in pressure compensator valve (16). The low pressure cut-in valve in pressure compensator valve (16) will upstroke the pump in order to maintain minimum pressure in the circuit.
Illustration 9 g00516791
(8) Steering pump case drain filter (10) Steering hydraulic oil tank (13) Breaker relief valve (18) Steering oil temperature sensorInternal leakage from steering piston pump (12) is returned to steering hydraulic tank (10) through steering pump case drain filter (8). Steering pump case drain filter (8) is bolted to steering hydraulic tank (10). Return oil from the steering system flows through steering filter (9). Steering filter (9) is located inside the steering hydraulic tank. Normally, oil flows through these filters and clean oil is returned to steering hydraulic tank (10). The steering pump case drain filter (8) and steering filter (9) will stop any debris that is in the oil.If any filter element becomes